Telephone receiver



June 14, 1927- NORDENSWAN TELEPHONE RECEIVER Filed Oct. 31, 1923 Patented June 14, 1927.

UNITED STATES PATENT OFF 1,631,978 ICE.

ROBERT NORDENSWAN, OF NEW YORK, N. Y., ASSIGNOR T0 WESTERN ELECTRIC COM- PANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE RECEIVER.

Application filed October 31, 1923. Serial No. 671,869.

This invention relates to telephone receivers and its object is to provide a telephone receiver, the operation of which is unaffected by temperature changes.

In general, the invention provides a telephone receiver in which. the clamping means has substantiallythe same coefficient of expansion as that of the diaphragm and means are provided to insure a positive and uni form clamping pressure at all points.

.In its preferred embodiment, the invention provides a receiver with a diaphragm mounting consisting of an iron clamping member and an iron seat in threaded en-- gagement therewith between which the diaphragm is clamped, pressure being exerted on the diaphragm through an iron ring having a plane clamping surface disposed. against the diaphragm and a soft copper gasket between said ring and clamping memher.

The drawing shows a cross section of a receiver embodying the invention. The electromagnetic unit 2, preferably of the type disclosed in Patent 1,273,351, July 23, 1919, H. A. Frederick, is mounted in a cup 3 preferably of non-magnetic material. Threadedly engaging the cup 3 is an annular seat 4 of iron or any material having the same coeflicient of expansion as that of diaphragm 5 seated thereon in operative relation to the electromagnetic unit 2. The cap of the receiver consists preferably of a clamping ring 6 of iron or some material having the same coefiicient of expansion as that of the diaphragm 5 and an earpiece 7 preferably of insulating material. such as hardrubber, threadedly engaging the clamping member 6. Between the clamping member 6 and the diaphragm 5 is disposed a metal ring 8 such as iron or some material having the same coefiicient of expansion as the diaphragm.

The narrow plane surface of ring 8 is disposed against the diaphragm and a yielding.

gasket 9 of copper, or other soft material, through which the pressure of the clamping ring 6 is transmitted to the ring 8 is disposed between the member 8 and ring 6. The clamping ring 8 being of hard material insures a positive and unvarying clamping surface, and the gasket 9 being of.

soft material insures the pressure exerted by clamping ring 6 being evenly distributed around the diaphragm. The inner surface of the angular member 4 is provided with an annular recess 10 in which is fitted a plate 11 having a central openingthrough which the receiver pole pieces extend. Between the plate 11 and the diaphragm 5 is disposed a plurality of annular disks 12 of aluminum foil orpaper for damping the vibrations of the diaphragm 5, the :total. thickness of the disks 12 when compressed being slightly less than the distance between the plate 11 and the-diaphragm 5.

. While the invention has been illustrated 1n connection with a telephone receiver, it

may be employed in telephone transmitters and phonograph reproducers and recorders.

It 1s especially suitable for instruments which are to be used in connection with scientific investigations and as standards of compamson.

What is claimed is:

1. In a receiver, a diaphragm, a seat therefor, a clamping member engaging said seat, a ring disposed against said diaphragm and a yielding metal gasket between said ring and said clamping means, whereby the clamping pressure is distributed uniformly on said diaphragm.

p 2. In a telephone receiver, a diaphragm. a seat therefor having a plane surface, a ringhaving a plane surface disposed against said diaphragm, a yielding metal gasket disposed against said ring, a clamping member engaging-said seat to secure said diaphragm,

said clamping member, said seat, said ring,

and said diaphragm having the same co efficient of expansion.

3. In a telephone receiver, a seat, an annular ring, a diaphragm between said ring and said seat, a metal clamping member, said diaphragm, said seat and said ring having the same coefficient of expansion. and' a yielding metal gasket between said clamping member and said ring whereby uniform pressure maybe exerted upon said diaphragm.

4. In a telephone receiver, a diaphragm, a seat, an annular member and clamping means for clamping said diaphragm between said seat and said annular member, all of said parts being constructed of materials having the same coefficient of expansion.

In witness whereof, I hereunto subscribe my name this 26 day of October'A. D. 1923.

ROBERT NORDENSWAN. 

